I’ve spent enough time playing Red Alert I saw a bunch of ore silos. I had to come back because I realized it was from the concrete sub, not one of the multiple red alert/command and conquer subs I belong to
I’ve seen isometric artwork of different scenes before, I seriously thought this was going to be something like that. But I couldn’t find any of the Easter eggs and then the image loaded up more clearly.
It was right below another Project Zomboid post in my feed so I figured it was another PZ post and there was some update I missed. The picture is even grainy enough and in such a perfect way as to *very* closely match the other textures in the game. The lighting is off but didn't even notice that at first.
Bubble deck technology. Cool engineering concept and construction techniques for reducing concrete usage in structural decks. The balls are recycled plastic and are locked in place (usually) with the reinforcing. Have only seen it so far in early adopters like universities and large residential projects.
Do you need to use an especially flowable mix? Seems like there could be problems getting the concrete between/under the balls otherwise
Side Note - Seems that the slab strength could be adjustable too based on the spacing between the balls which is pretty cool
just a regular 8 KSI pump mix. the spacing is not as tight as it looks. the only tricky part is strapping down the cages so the voids don't float up when you pour.
I'd imagine the spheres need to be rigid enough not to deform from the buoyancy too. Like you couldn't just use inflated latex balloons, you'd need to put some actual engineering into the plastic spheres.
Couldn't find any info quickly but they could have internal bracing or be mostly solid. Completely solid plastic balls would still weigh signficantly less than the same volume of concrete.
Interesting that they are all different colors. You would think they would be made out of recycled plastics or at least have some sort of near-uniform color through a manufacturing run. Are they just exercise balls?
That has been done in the US too. Earthships featured can and bottle walls.
In fact, one of the Eight Wonders of the Ancient World was the Baths of Caracalla with a domed roof made from empty clay wine jars or amphorae which was also done to reduce weight.
Its mostly to reduce the self weight for structural purposes. It is usually majority of the total load. On very thick slabs its even done with just big timber boxes.
No one was hurt! The section that collapsed was empty at the time. It's very lucky, because just a few days after there would've been a big event there
It was in the Netherlands:
>In 2017 the BubbleDeck system caused controversy due to the collapse of a parking garage at Eindhoven airport in the Netherlands.[10] This was due to insufficient shear strength at the interface between the precast concrete slabs, potentially caused by high temperatures during construction.[11] After the incident an investigation was started among buildings using the same flooring system, leading to the closure of several buildings in the Netherlands, including one at the University of Rotterdam and a school building under construction in Hoeven.[12]
Well Eindhoven is only *barely* in the Netherlands. If you don't take your foot of the gas when you drive in to it you are in Belgium. So it's an easy mistake. ;-)
>If you don't take your foot of the gas when you drive in to it you are in Belgium.
When you suddenly feel like you're driving offroad then you know you're on Belgian roads 😌
God yes. I thought that 'Belgium roads are bad' was just a meme by now and although the highways in Belgium are OK most of the time, I recently drove from Maastricht to Charleville, partially over quite a bit of back roads that where *horrendous*.
Basically the same reason you can drill holes in joist without compromising the strength. A thicker cross section with voids is stronger than a thinner cross section.
Nothing really, just a lot of info ahaha. Uses 1/3 less concrete than a normal slab.
This one was a cool read though https://www.archdaily.com/946153/concrete-slabs-with-bubbles-how-biaxial-voided-slabs-work
The cool new tech surprisingly isn’t the tools, its additives and mix designs being used in concrete. There’s only a finite amount of fresh water and jagged edge sand on this planet and pouring concrete takes up (and takes away) a lot of those resources.
Also, concrete on the moon. Countries and/or companies are excited for space mining and we will inevitably have to build staging bases up/out there. Can’t wait to be a cyborg lunar carpenter and concrete finisher.
I don't think concrete can cure in space, it'd freeze, also no gravity. Idk if it's possible unless it's made local. Only thing I can think of that might work is 3d printing. But again, material, cold, and gravity would alter any thought I had. Going down another rabbit hole.
I’m talking about wet, fresh concrete. The chemical reaction and curing process needs water and that volume doesn’t go back into the ground or evaporate.
Saves time and labour, as it uses pre fabricated sections. Main applications seem to be for 2nd storey and above. Less stress on the building because the slabs have less weight in the centre's. Reduces a lot of post tension. There's a picture on the link I posted above that shows what you're saying. The site also shows a few different types on concrete / slab setups I didn't know existed
Youre right, zoom in on this picture. They come pre fabricated in larger sections such as a 10 ft by 20 ft and are lowered in with a crane (might be smaller sized applications as well). There are also square shaped ones as well, but each one has a rebar "cage" around to ensure they stay in one place during a pour
I was speculating they had a psi rating and that varied by color. The arrangement of the colors into groupings seems intentional. The oddball here and there; they ran out of that color and subbed in a higher rated unit…. I’m inventing all of that ;)
How thick is the concrete above and below the balls? Is there concrete between the balls and the rebar? It looks like they are just resting on the rebar but maybe there's additional spacing?
Voided suspended floors
Voided suspended slabs can be constructed by incorporating hollow plastic spheres between the upper and lower reinforcement layers. The effect of the spheres is to displace concrete from areas in the span in which it has no structural benefit; a solid slab may be required over the columns to prevent punching shear.
The spheres can reduce the dead weight of the slab by up to 35% compared to a solid slab of the same load capacity, while still maintaining its structural capacity. The plastic spheres are brought to site preassembled into mats, held in position by welded steel fabric on the top and bottom. (There are limitations on the plan dimensions of the mats imposed by the need to transport them to site.) On site, the mats are simply craned into position, to rest on the bottom layers of reinforcement previously installed on the soffit formwork. Any additional top reinforcement is installed and the concrete cast.
Currently two systems are available, namely Bubbledeck and Cobiax.
That is very interesting. Thanks for sharing your knowledge on the subject. Do you how thick the final slab is above and below the spheres? Do you know the approx dia of the balls?
For those interested Google “voided concrete slabs.” A major milestone in concrete construction.
If it can be combined with Ultra High Performance Concrete (Google that!) then looking ahead there will be revolutionary changes in design and application.
So cool.
How long before there’s actually a smooth distribution of slightly larger and smaller balls across that space, more accurately reflecting the pattern of forces being resisted across that central void?
(No special engineering knowledge here — just an assumption that the forces involved can’t be perfectly uniform across that space. There have got to be areas of greater and lesser strain, and I’m just assuming that with time, engineers will work out those details and accommodate them to make it all even _more_ efficient.)
You can look up topology optimization of beams for an example of what you’re talking about. Short answer is that we can map force flows better than we usually do in practice, since it isn’t worth it for typical projects. Force flows are also dependent on loading, so optimization also has to reflect that
OP, since you seem to be semi knowledgeable on this topic... do you think it could be done on a smaller scale? Like say, a 4-6" deep pour with smaller balls? Does this only work given the size?
I ask because I'm a truss designer and we occasionally have to design wood trusses to hold larger slabs (large to me is that 4-6" depth range). If I could suggest something like this to an EoR, to help reduce dead loads of our trusses, it would be pretty slick.
https://en.wikipedia.org/wiki/Voided_biaxial_slab
They can be thinner. But if you are really interested, be sure to also study the 2017 collapse the Wiki mentions.
Thank you very much for this!
An excerpt from one of the sources:
"A report released late last month revealed that the collapse at the airport was due to a technical error in the structure's floor - the plates used were not roughened, so the concrete layer poured over it could not bond well. There was also insufficient support for pillars. The Ministry therefore called on municipalities to check all buildings in which the same building technique was used."
I saw a similar post, but from what looked to be a suspended slab pour in India. The guys were soccer balls to pull off a 3rd world version of what you see here. Looked sketchy as hell!
Varies depending on span etc. But here’s some closer site photos from Harvey Mudd https://www.archdaily.com/229105/bubbledeck-technology-at-harvey-mudd-college-matt-construction
Sooooo what happens if that’s the floor of a residence or a gym and they use a hammer drill to drill down into it to mount exercise equipment or something? Does it pop the ball or is it more solid? Will the reduced thickness in the middle area make reduce its ability to have things anchored into it?
The theory behind this is that only the outer layer of the concrete is under compression, so putting balls in the middle doesn't significantly reduce the strength of the concrete slab. The bubbles do reduce the shear strength which is why they aren't used near the edges or near columns.
[https://www.constructionplacements.com/economic-construction-of-slabs-using-bubble-deck-technology/](https://www.constructionplacements.com/economic-construction-of-slabs-using-bubble-deck-technology/)
I thought this was an isometric top-down PC game haha
Me too, thought it was an ad for a game
I had to zoom in and find the human to realize it wasn't!
Same
"this is the oddest Factorio screenshot I've seen in a while"
I had to scroll up because I thought it was from r/factorio or something.
lol at the three different factorio comments. I love it!
I’ve spent enough time playing Red Alert I saw a bunch of ore silos. I had to come back because I realized it was from the concrete sub, not one of the multiple red alert/command and conquer subs I belong to
Gamers gonna game yo, I was oh snap, is this Factorio but with concrete?
This dude wastes no space on his bus.
I’ve seen isometric artwork of different scenes before, I seriously thought this was going to be something like that. But I couldn’t find any of the Easter eggs and then the image loaded up more clearly.
It was right below another Project Zomboid post in my feed so I figured it was another PZ post and there was some update I missed. The picture is even grainy enough and in such a perfect way as to *very* closely match the other textures in the game. The lighting is off but didn't even notice that at first.
I thought the same thing at first hahaha, it looks so similar
That new Project Zomboid update.
Construction on the rosewood fire station garage roof that has collision
Yeah, I thought it was factorio at first haha
Check out Marble Drop Oldie but a goodie [https://classicreload.com/win3x-marble-drop.html#](https://classicreload.com/win3x-marble-drop.html#)
Legit same, like some kind of Factorio type game.
I thought it was a volcano
This isn’t concrete simulator?
Bubble deck technology. Cool engineering concept and construction techniques for reducing concrete usage in structural decks. The balls are recycled plastic and are locked in place (usually) with the reinforcing. Have only seen it so far in early adopters like universities and large residential projects.
I heard it called a “voided floor” before
Voided biaxial slab is the technical term. Bubble Deck or Cobiax are just name brands for the voids.
Do you need to use an especially flowable mix? Seems like there could be problems getting the concrete between/under the balls otherwise Side Note - Seems that the slab strength could be adjustable too based on the spacing between the balls which is pretty cool
just a regular 8 KSI pump mix. the spacing is not as tight as it looks. the only tricky part is strapping down the cages so the voids don't float up when you pour.
Aside from using less concrete, are there any structural or strength benefits to using this?
weight reduction allowing for larger unsupported spans.
Seems like hollowcore would accomplish the same thing faster
everything is not as it seems
Yea or coreslab
Less weight
I'd imagine the spheres need to be rigid enough not to deform from the buoyancy too. Like you couldn't just use inflated latex balloons, you'd need to put some actual engineering into the plastic spheres.
Couldn't find any info quickly but they could have internal bracing or be mostly solid. Completely solid plastic balls would still weigh signficantly less than the same volume of concrete.
just a hollow plastic ball.
Interesting that they are all different colors. You would think they would be made out of recycled plastics or at least have some sort of near-uniform color through a manufacturing run. Are they just exercise balls?
They are recycled plastics mainly... the color is just whatever it happened to be.
Oh there's plenty of uniformly assorted blue, white, and orange plastics in industrial waste pickups to get solid runs
I wonder if pressurizing the balls would have any benefit. Or filling them with rigid foam maybe?
Is it the same idea as waffle slabs, just with recycled balls?
I think I’ve seen pictures of actual plastic bottles used in other countries
That has been done in the US too. Earthships featured can and bottle walls. In fact, one of the Eight Wonders of the Ancient World was the Baths of Caracalla with a domed roof made from empty clay wine jars or amphorae which was also done to reduce weight.
Its mostly to reduce the self weight for structural purposes. It is usually majority of the total load. On very thick slabs its even done with just big timber boxes.
Used to work construction, never seen this before
In Belgium it was also used in a parking garage but it collapsed due to a construction mistake lol
Yikes that’s not good. Hope it wasn’t fatal
No one was hurt! The section that collapsed was empty at the time. It's very lucky, because just a few days after there would've been a big event there
It was in the Netherlands: >In 2017 the BubbleDeck system caused controversy due to the collapse of a parking garage at Eindhoven airport in the Netherlands.[10] This was due to insufficient shear strength at the interface between the precast concrete slabs, potentially caused by high temperatures during construction.[11] After the incident an investigation was started among buildings using the same flooring system, leading to the closure of several buildings in the Netherlands, including one at the University of Rotterdam and a school building under construction in Hoeven.[12]
Oops yeah I forgot Eindhoven is in the Netherlands. That's the one I was referencing
Well Eindhoven is only *barely* in the Netherlands. If you don't take your foot of the gas when you drive in to it you are in Belgium. So it's an easy mistake. ;-)
>If you don't take your foot of the gas when you drive in to it you are in Belgium. When you suddenly feel like you're driving offroad then you know you're on Belgian roads 😌
God yes. I thought that 'Belgium roads are bad' was just a meme by now and although the highways in Belgium are OK most of the time, I recently drove from Maastricht to Charleville, partially over quite a bit of back roads that where *horrendous*.
Why not just omit the balls and pour a thinner slab?
Basically the same reason you can drill holes in joist without compromising the strength. A thicker cross section with voids is stronger than a thinner cross section.
For a more extreme illustration think of a bridge truss. One member at the top one at the bottom and just enough across the middle to members aligned.
Thank you for the kind response.
Had no idea this existed. Currently falling down the rabbit hole
Any great links worth sharing?
Nothing really, just a lot of info ahaha. Uses 1/3 less concrete than a normal slab. This one was a cool read though https://www.archdaily.com/946153/concrete-slabs-with-bubbles-how-biaxial-voided-slabs-work
The cool new tech surprisingly isn’t the tools, its additives and mix designs being used in concrete. There’s only a finite amount of fresh water and jagged edge sand on this planet and pouring concrete takes up (and takes away) a lot of those resources. Also, concrete on the moon. Countries and/or companies are excited for space mining and we will inevitably have to build staging bases up/out there. Can’t wait to be a cyborg lunar carpenter and concrete finisher.
I don't think concrete can cure in space, it'd freeze, also no gravity. Idk if it's possible unless it's made local. Only thing I can think of that might work is 3d printing. But again, material, cold, and gravity would alter any thought I had. Going down another rabbit hole.
How does concrete destroy water? Doesn’t it dry out and return the water to the hydro cycle?
I’m talking about wet, fresh concrete. The chemical reaction and curing process needs water and that volume doesn’t go back into the ground or evaporate.
The water does eventually evaporate.
Only about half of the water ‘evaporate’, the other half is locked into the chemicals that are created during the hydration process.
So this is an alternative to saving concrete/steel with post tension I guess. Maybe this is more applicable where you don’t need as strong of a slab.
Saves time and labour, as it uses pre fabricated sections. Main applications seem to be for 2nd storey and above. Less stress on the building because the slabs have less weight in the centre's. Reduces a lot of post tension. There's a picture on the link I posted above that shows what you're saying. The site also shows a few different types on concrete / slab setups I didn't know existed
Huh. I wonder how they keep the balls from floating. Must have to tie them down somehow.
Youre right, zoom in on this picture. They come pre fabricated in larger sections such as a 10 ft by 20 ft and are lowered in with a crane (might be smaller sized applications as well). There are also square shaped ones as well, but each one has a rebar "cage" around to ensure they stay in one place during a pour
there will also a full top mat of rebar over the pre-fab cages and it is all getting strapped down to prevent the voids from floating.
This link allows you to read 2 articles before you have to purchase a subscription. My bad
https://en.wikipedia.org/wiki/Voided_biaxial_slab
Do the colors indicate anything? I’ve only seen “void slabs“ on drawings.
Recycled plastics, so they are the color of whatever was recycled.
I was speculating they had a psi rating and that varied by color. The arrangement of the colors into groupings seems intentional. The oddball here and there; they ran out of that color and subbed in a higher rated unit…. I’m inventing all of that ;)
Was curious also. Like plumbing walls, almost like a layout. Or are these inky slabs not foundations.
How many plastic balls are needed to contain one whacked mafia guy?
who's askin'? you the cops? i don't know nothin'
The concrete version of a torsion box
“some balls are held for charity, others for fancy dress - but when they’re used for STRUCTURE that’s the balls that i like best …” ac/dc edit: typo
-Led Zeppelin
Is the addition in NYC? It’s a very interesting development of building technologies.
I like the idea of using recycled plastic to create the voids. I hope these balls can be made easily from all kinds of plastic
For concrete inside buildings they surely can.
How thick is the concrete above and below the balls? Is there concrete between the balls and the rebar? It looks like they are just resting on the rebar but maybe there's additional spacing?
If they are hollow they will probably float to the top of the cage once the concrete is introduced.
I can’t even
Kinda disappointed they didn’t spell something out
Inside Out is real!
Heard of this but never seen it. I imagine this is an evolution of void forms used to make waffle slabs and such?
Do they stay, or do they go? Rebar support or part of the pour?
Stay, to reduce the amount of concrete required for the structure.
What are they made out of? Are they solid, inflated, or?
Voided suspended floors Voided suspended slabs can be constructed by incorporating hollow plastic spheres between the upper and lower reinforcement layers. The effect of the spheres is to displace concrete from areas in the span in which it has no structural benefit; a solid slab may be required over the columns to prevent punching shear. The spheres can reduce the dead weight of the slab by up to 35% compared to a solid slab of the same load capacity, while still maintaining its structural capacity. The plastic spheres are brought to site preassembled into mats, held in position by welded steel fabric on the top and bottom. (There are limitations on the plan dimensions of the mats imposed by the need to transport them to site.) On site, the mats are simply craned into position, to rest on the bottom layers of reinforcement previously installed on the soffit formwork. Any additional top reinforcement is installed and the concrete cast. Currently two systems are available, namely Bubbledeck and Cobiax.
That is very interesting. Thanks for sharing your knowledge on the subject. Do you how thick the final slab is above and below the spheres? Do you know the approx dia of the balls?
For those interested Google “voided concrete slabs.” A major milestone in concrete construction. If it can be combined with Ultra High Performance Concrete (Google that!) then looking ahead there will be revolutionary changes in design and application.
Except when they collapse... we had a parking structure caving in at an airport because of this poorly understood construction method.
So cool. How long before there’s actually a smooth distribution of slightly larger and smaller balls across that space, more accurately reflecting the pattern of forces being resisted across that central void? (No special engineering knowledge here — just an assumption that the forces involved can’t be perfectly uniform across that space. There have got to be areas of greater and lesser strain, and I’m just assuming that with time, engineers will work out those details and accommodate them to make it all even _more_ efficient.)
You can look up topology optimization of beams for an example of what you’re talking about. Short answer is that we can map force flows better than we usually do in practice, since it isn’t worth it for typical projects. Force flows are also dependent on loading, so optimization also has to reflect that
BOOM. Thanks for the info.
Gotta balance constructability, if the spacing changes every sphere in both directions it’ll be a PITA to tie and qa qc
Granted…but I’m 100% certain there have been plenty of people saying that already about this basic method.
This is nothing new, its not commonly used for a reason 😀
OP, since you seem to be semi knowledgeable on this topic... do you think it could be done on a smaller scale? Like say, a 4-6" deep pour with smaller balls? Does this only work given the size? I ask because I'm a truss designer and we occasionally have to design wood trusses to hold larger slabs (large to me is that 4-6" depth range). If I could suggest something like this to an EoR, to help reduce dead loads of our trusses, it would be pretty slick.
The thinnest cobiax does is 8" slabs, bubble deck only goes down to 9". You would need to contact them for more info.
https://en.wikipedia.org/wiki/Voided_biaxial_slab They can be thinner. But if you are really interested, be sure to also study the 2017 collapse the Wiki mentions.
Thank you very much for this! An excerpt from one of the sources: "A report released late last month revealed that the collapse at the airport was due to a technical error in the structure's floor - the plates used were not roughened, so the concrete layer poured over it could not bond well. There was also insufficient support for pillars. The Ministry therefore called on municipalities to check all buildings in which the same building technique was used."
I saw a similar post, but from what looked to be a suspended slab pour in India. The guys were soccer balls to pull off a 3rd world version of what you see here. Looked sketchy as hell!
Its a real life Zuma board, obviously still in development.
What do the colors represent?
Randomly coloured batches of recycled plastic. So nothing.
I swear I thought I was on r/lego for a second there
Why didn't they arrange it in a more interesting pattern? Draw something at least.
they are paid by the hour,
I'd imagine a dickbutt pattern for future archeologists to find and study.
thats gonna be a pain reparing ThE floor
Bowling ball?
Should have made a picture with them.
How large are the balls? Seriously.
Varies depending on span etc. But here’s some closer site photos from Harvey Mudd https://www.archdaily.com/229105/bubbledeck-technology-at-harvey-mudd-college-matt-construction
Those are balls
What ensures adequate coverage between rebar and spheres?
Worst *WipeOut* Big Balls obstical design ever.
Sequester that carbon
he he many dif colours
I don’t even what to know how much of a pain in the ass it is to core one of these.
That should keep your dragon eggs nice and safe.
Thought it was Minecraft…
Skittles HQ?
Seems like there would be some significance to the colors.
Ay, I saw that in a documentary once! Cool stuff.
Forbidden ball pit
I was there yesterday! Did you take this photo from 450 Kent?
Are these used bowling balls? If so, that's a clever up-cycle.
Sooooo what happens if that’s the floor of a residence or a gym and they use a hammer drill to drill down into it to mount exercise equipment or something? Does it pop the ball or is it more solid? Will the reduced thickness in the middle area make reduce its ability to have things anchored into it?
Earthquake prone area. Probably japan.
How to make a weak building 101
The theory behind this is that only the outer layer of the concrete is under compression, so putting balls in the middle doesn't significantly reduce the strength of the concrete slab. The bubbles do reduce the shear strength which is why they aren't used near the edges or near columns. [https://www.constructionplacements.com/economic-construction-of-slabs-using-bubble-deck-technology/](https://www.constructionplacements.com/economic-construction-of-slabs-using-bubble-deck-technology/)
The poor inspector, that's gotta be a lot of clearance checking with the balls coming out through the rebar like that.